Might be the stupidest question ever but here goes. If hp so the product of work that torque made. Would it be safe to assume its the tq that is usually the culprit at blows engines and not hp?

 

Horsepower is calculated from torque...so whatever torq you have at certain rpm's, it will dictate the hp value.

As an example, take whatever dyno graph and check what happens at 5250 rpm's...

However, your question is valid. Just put it different way: what is the reason for engine breaking into pieces? Well, I guess there are many reasons. When something fails (fuel pressure, meth, etc.), that's fairly typical reason for engine loosing a piston.

Having too much cylinder pressure - without knocking - may cause things to break. And timing. And so on.

 

As Pekka mentioned one is a function of the other. As long as RPM exists, then one cannot exist without the other. At any given RPM, they are directly proportional. You raise torque and horsepower will also come up, but they don't rise in parallel due to the equation Torque * RPM / 5252.

That means at half the RPM, you have to double the torque to come up with the same HP value. That's why you can't hit nitrous at idle and need to wait for a higher RPM. a true 200 shot of nitrous will make 200ft lb of torque at 5252RPM and therefore 200 horsepower, but will also make 400ft lb of torque at 2727RPM and an additional 800 ft lb of torque at 1363.5 RPM. Torque is a direct result of actual yielded cylinder pressure, so if looked at that way, yes torque can kill a motor. Conversely, RPM is hard on motors mostly due to reciprocating weight and loss of control of certain items as RPM increases, so applying pressure in tandem with having to deal with the reciprocating masses is also a killer.

People say TQ wins races. I can argue that. Ever seen one of those old time water wheels used to run a mill or something? The one that has a stream running into it to fill little reservoirs on the circumference of the wheel. Consider that wheel can make 3000ft lb of torque. Can that wheel beat your Vette? Why not? because horsepower is used to determine actual work done or ability to do work. That wheel turns 2 RPM. Now how much power does it make? 1.14 horsepower. So lets take it further. I've heard many people say "torque wins races". Really? OK! bring your wheel over and lets do this! Let's say it makes 10,000 ft lbs. Now can it compete? That's almost 5hp! What? if you gear it properly, you can win? Ok. Let's gear it. Based on the transmission and differential you found for your wheel, you discovered you need the shaft to turn 2000RPM so that you can hit your speed target at the end of the track. You just divided your torque by 1000 and your resultant torque is 10 ft lbs before taking the frictional losses into account.
If you add a tweak to the statement it is more acceptable "with all other things being equal including RPM, weight and traction, torque wins races" , but it's stating the blatantly obvious.

A little side tracked, but I felt like it needed to be put out there.

 

Another not so relevant comment is related to drivetrain. It is the torque that breaks your drivetrain.

Anyway, all this torq. vs. hp has a relevance and it's not that easy to explain it in couple of sentences. I'll let better educated folks to continue.

 

And I'll add to that in that it depends on how the torque is applied. I've seen things take a nicely applied 1000ft lb of torque and break when you shock it with 500.
Wheel hop is my best example of that.
Second is the impact wrench. There is no substitute for that shock applied along with the torque.

 

I'll play along......at what point in the rpm range is "your" car accelerating the quickest/hardest down the track ??

Why is shift recovery and rpm drop important ??

Which of these cars would be quicker (identical cars/drivetrains)
600rwtq@4900 rpm....or....600rwtq@5900 rpm ??



.

 

I would think it would be whichever of the 2 cars makes more power under the curve. So if you were to measure the area underneath the graph of torque within the RPM range that is being used.

That is my amateur opinion and I may be very wrong

 

My answer is which ever car I'm not driving.

No seriously though there's a lot of variables and one of the major ones would be the driver. But assuming all things are equal obviously the car with the same TQ at the lower RPM would be quicker (in a perfect world)

 

What is your "usefull" rpm range going down the track (where do you shift and what does it fall back to) ??

Whats peak tq rpm and what is the tq @ peak hp ??

.

 

and that's how i've kept my otherwise-stock LS1/T56 intact while making a minimum of 500lb-ft from 2500-5000rpm

if i was running the RXT clutch i'll eventually get & started dumping it at 4000 from a dig, i wouldn't expect anything downstream of my Maggie to last more than a few times of that.
i've been mindful to roll into the power til i can afford to beef stuff up some more

 

but then again...
if'n i break something, it's more of an excuse to convince the wife to let me fix it with something better

 

Just to refresh your memory......In my world...and yours for that matter, the most torque at the most RPM always wins!!!!!Do you know why? Torque x RPM divided 5252 = Horsepower.SO, if you have the biggest torque x the most RPM divided by 5252 will make the Biggest HP number...PERIOD. And just to be clear....we are talking WHEEL torque(what it makes at the tire).....


*

 

If on nuts i take number 2.

 

Agreed. Weren't we talking about something slightly different though?

 

The answer is: with equal weight, traction, aerodynamics and drivetrains behind the engine etc., the one that makes the highest average horsepower will be quickest and the one that makes the highest horsepower will be fastest.

 

 

Ummmmm.....isnt that what I stated and of course you can only campare equal vehicles ?? (half empty/half full...)

 

pretty much.
the power under the curve is pretty representative of the average horsepower

 

Peak tq is where maximum cylinder pressure is and....is typically the most timing sensitive rpm area, which by nature would expose the "weak links" in combo (like; chamber design, blow down inefficiencies, valve events..etc).

 

I agree with average power but show me a "better" average in a usefull "band" ??

Example; I shift a roughly 7100 and drop to roughly 5400 rpm (average per gear), this is the only range Im concerned with. So in 1650 rpm swing the "average " wins....but a better way to explain it is......the guy how carries the most rwtq the highest and longest wins.....